Field of the Invention
The present invention relates to a measuring device and an operating method of a measuring device.
Priority is claimed on Japanese Patent Application No. 2017-002461, filed Jan. 11, 2017, the content of which is incorporated herein by reference.
Description of Related Art
In order to perform a nondestructive appearance test for damage and corrosion of the inside of an engine, a turbine, a chemical plant, and the like, industrial endoscopes are widely used. When defects such as damage and corrosion are found, it is necessary to switch between countermeasures in accordance with the degree thereof. For this reason, there are industrial endoscopes having a measuring function for measuring the magnitudes of damage and corrosion.
For example, as shown in Japanese Unexamined Patent Application, First Publication No. 2004-49638, a measurement endoscope device includes two optical systems having parallax. The measurement endoscope device simultaneously captures optical images acquired by the optical systems. The measurement endoscope device calculates the three-dimensional coordinates of a subject and the size of the subject on the basis of the principle of stereo measurement by using the two images that are generated.
A stereo measuring device disclosed in Japanese Unexamined Patent Application, First Publication No. 2010-128354 includes an optical system that forms two images of a subject formed by light passing through two different optical paths in a common area of imaging devices. The two different optical paths are referred to as a first optical path and a second optical path. In addition, the stereo measuring device includes an optical path switching means that performs switching between the optical paths to capture a subject image formed only by light passing through one of the two optical paths.
In a case in which measurement of a subject is performed using the stereo measuring device disclosed in Japanese Unexamined Patent Application, First Publication No. 2010-128354, an image (referred to as a first image) is generated through imaging based on a first subject image formed by light passing through the first optical path. Subsequently, the optical path is switched, and an image (referred to as a second image) is generated through imaging based on a second subject image formed by light passing through the second optical path. The shape of the subject is measured using the principle of stereo measurement on the basis of a parallax between the first image and the second image.
In a measurement endoscope device disclosed in Japanese Unexamined Patent Application, First Publication No. 2004-49638, two subject images formed by light passing through two optical paths are formed in different areas of an imaging device. In contrast to this, in the stereo measuring device disclosed in Japanese Unexamined Patent Application, First Publication No. 2010-128354, two subject images formed by light passing through two optical paths are formed in a common area of an imaging device. For this reason, in the stereo measuring device disclosed in Japanese Unexamined Patent Application, First Publication No. 2010-128354, the imaging area can be increased, and the quality of a captured image can be improved.
On the other hand, in the technology disclosed in Japanese Unexamined Patent Application, First Publication No. 2010-128354, as an endoscope moves while the first image and the second image are captured, an error occurs in a parameter (a baseline length or the like) of the stereo measurement. For this reason, the shape of the subject cannot be accurately measured. A technology for solving this is disclosed in Japanese Unexamined Patent Application, First Publication No. 2016-14896.
An endoscope device disclosed in Japanese Unexamined Patent Application, First Publication No. 2016-14896 alternately captures a first image and a second image. When a positional deviation amount between two first images or two second images is below a predetermined threshold, the endoscope device determines that there is no shaking of the device and performs a measurement process.